It’s a safe bet that not many teachers are avid readers of the medical journal Pediatrics. But a report that appeared in the publication last week deserves to be read and understood deeply by everyone in education. It has the potential to transform the way we think and speak about children who grow up in poverty–and education as a means of addressing its worst effects.

The report links “toxic stress” in early childhood to a host of bad life outcomes including poor mental and physical health, and cognitive impairment. The American Academy of Pediatrics (AAP), in an accompanying policy statement, calls on its members to “catalyze fundamental change in early childhood policy and services” in response.

The term “toxic stress” is not a familiar one in education circles, but it should be. The Harvard Center on the Developing Child describes a toxic stress response as occurring “when a child experiences strong, frequent, and/or prolonged adversity—such as physical or emotional abuse, chronic neglect, caregiver substance abuse or mental illness, exposure to violence, and/or the accumulated burdens of family economic hardship—without adequate adult support.” Think of it as one plus one equals negative two: something bad happens to a child, and there’s no positive adult response to mitigate the trauma. The lack of adult support is what makes stress, which is largely unavoidable, “toxic” to a child. Crucially, repeated or prolonged activation of a child’s stress response system “can disrupt the development of brain architecture and other organ systems, and increase the risk for stress-related disease and cognitive impairment, well into the adult years,” notes the Center’s website.

This cannot be dismissed as pseudoscience or a mere hypothesis. The report and policy statement notes a “strong scientific consensus” and a growing body of research “in a wide range of biological, behavioral, and social sciences,” on “how early environmental influences (the ecology) and genetic predispositions (the biologic program) affect learning capacities, adaptive behaviors, lifelong physical and mental health, and adult productivity.”

“Game changer” is a trite and overused phrase, but it applies here. The report should have a profound impact on educators and education policymakers. At the very least, understanding the language and concept of exposure to toxic stress should inform the increasingly acrimonious, dead-end debate about accountability and resources aimed at the lowest-performing schools and students.

On the one hand, those who insist that improving educational outcomes must be viewed within a broader context of health care, community resources and poverty can claim a victory here and a potential ally in the AAP. Interventions must start from Day One. Not Day One of school, Day One of life. Kindergarten is too late. Those who favor quality preschool programs have crucial evidence to support their case. The story in four words: Geoffrey Canada is right.

But it is equally clear (or should be) that low-income status is not synonymous with toxic stress. Even the worst schools and poorest neighborhoods have a significant number of children from stable homes with engaged, caring adults, who are able to provide the consistency and nurturing necessary to buffer the negative effects of even the most traumatic stressors. “Research shows that, even under stressful conditions, supportive, responsive relationships with caring adults as early in life as possible can prevent or reverse the damaging effects of toxic stress response,” according to the Harvard Center on the Developing Child.

To this end, no less than pediatricians, schools and teachers–especially in early childhood– have an essential role to play. In the absence of nurturing relationships at home, children may be able to find the support they need within the educational environment. According to Rebecca Schrag, Ph.D., psychologist at Healthy Steps at Montefiore Medical Center, supportive adult relationships “can no longer be considered the ‘touchy-feely’ domain of child psychologists alone. Rather, there is hard science suggesting that they are perhaps the number one protective factor against the negative outcomes of a range of stressors. The AAP has made a huge step forward in releasing its policy statement on toxic stress, and it would be truly wonderful if other professionals who work with children – educators, most notably – followed suit.”

In light of the important role of supportive adult relationships, the takeaway here is clearly not that exposure to toxic stress makes it impossible for schools to succeed with low-income children. But it should make clearer that the bar is much, much higher for a significant number of kids who endure extreme levels of chaos and disruption in their lives, children whose brains – even by age 5 – show the deleterious effects of toxic stress exposure. This does not mean we should throw up our hands and say, “let’s not waste time and money on poor kids. It’s not going to work.” But it certainly puts the “No Excuses” mindset at a disadvantage, particularly when most children only begin school in kindergarten. Given the scientific consensus cited by the report, holding to the idea that schools or teachers should be able to reverse unilaterally the worst effects of toxic stress in all cases begins to sound ill-informed and hopelessly naïve.

At present, the standard reform recipe for improving educational outcomes for all children living in poverty is high expectations, improved teacher quality and muscular accountability. For many low-income kids, perhaps even most, this may indeed be enough. For others, more – much more – is clearly required. It is critical that educators and policymakers begin to differentiate between the two.

A few years ago John Cloud of TIME Magazine wrote that the idea that kids are overscheduled and need to slow down is “a fine example of transference. Aren’t you really the one who wants to lose the BlackBerry and go fishing?” Looks like he was right. The Washington Post takes note of new research that indicates kids not only cope with a heavy schedule, but thrive with it. It’s the parents, however, who are stressed out. And, (as is often the case when members of professional classes feel burdened by a problem) it’s not that much of an issue to begin with.

Two studies based on data about how children spend their days show that only a minority are heavily scheduled and that organized activities are linked to positive outcomes in school, emotional development, family life and behavior. The children most at risk have no activities at all, the studies showed.

“I found the opposite of what I expected,” Sandra L. Hofferth, director of the Maryland Population Research Center at the University of Maryland at College Park, tells the Post. Hofferth “started out with a pretty solid belief that lots and lots of activities are bad for children.” But, says the paper, she found a higher level of activity was not linked to such stress symptoms as depression, anxiety, alienation and fearfulness.

The American Academy of Pediatrics warned in 2006 that a hurried lifestyle could create anxiety or contribute to depression for some children.